Subject: Making progress on my new stove Mon Mar 02, 2015 4:50 am
gadily Moderator
Posts : 1477 Join date : 2013-12-08
Subject: Re: Making progress on my new stove Mon Mar 02, 2015 7:02 am
nice build there but i like your door cao
heres some screen shots of vortex if you want to do your own get vlc player and whilst playing them left click on video and left click on snapshot
fins are ok for creating a vortex but i believe they can cause a slow down or turbulance within the vortex
T2H Admin
Posts : 913 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Mon Mar 02, 2015 10:12 am
That looks pretty nice my friend! That fire produces a very cool geometric pattern!
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Mon Mar 02, 2015 2:27 pm
Thank you very much Gentleman for your replies.
gadily wrote:
fins are ok for creating a vortex but i believe they can cause a slow down or turbulance within the vortex
Probably you're right about the slowing down, but I have limited space for the stove and this system allows me to save about 20 to 25 cm length of stove. The "fins" or "deflectors" are placed at a 45 degree angle and fire flows ok at this angle. When I lit the fire the second time, within five minutes there was no smoke and it was burning at "full speed".
Gadily, thank you very much for your compliment on the door, but it is not my original idea. I got it from this fellow
I will make a video with the finished stove and details of the construction, but that will take some time.
T2H Admin
Posts : 913 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Thu Mar 05, 2015 1:31 am
Caotropheus I can see how this stove could be used with a thermal mass, you could encase the entire stove in a thermal mass and leave one spot on top of the stove as an open space so you could still cook on it if needed.
Pretty cool looking stove.
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Thu Mar 05, 2015 2:36 pm
Because of the lack of space and the need to move the stove during the Summer, I am just going to install the heat exchanger and flue collar. I am studying the possibility of installing a water heating coil, but not yet.
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Sun Mar 22, 2015 4:00 am
Finished the project, here it is, and I was too lazy to edit the video, so...
gadily Moderator
Posts : 1477 Join date : 2013-12-08
Subject: Re: Making progress on my new stove Sun Mar 22, 2015 5:50 am
I have to say that made one hell of a change seeing all of your build from the very start
loverly build of your stove and nice to see it working so well indeed
? can you shut one of your side vents down leaving the other open
on a further note as seeing it on another video when it fails just chop above the welded part for heat exchanger and use the shim method to reseal the system as goes for your vortex creator that can be changed out time and time again
spotted it on this video and i think its a good idea to use the method
from 3 mins in
change out proceeder is at 4.45 and i think its a damn good idea to have and use in any system for a change out to wear and tear on the system
T2H Admin
Posts : 913 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Sun Mar 22, 2015 6:59 am
Nice work Ca, you are doing some nice builds, soon those around you will be sending everyone to the local stove builder!
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Sun Mar 22, 2015 2:09 pm
Thank you very much. Yesterday the stove worked for 12 hours, without much effort and just loading 2 to 3 sticks (not full fire box load) the stove temperature was kept between 330ºC and 400ºC. Throughout this period, I think I reloaded the stove on an hourly basis.
Please comment.
David14324u
Posts : 2 Join date : 2014-11-01
Subject: Re: Making progress on my new stove Sun Mar 22, 2015 7:18 pm
I love your work and veriaty of designs and sharing with everyone . On ths stove Are you able to shut off secondary air to see if makes a difference also can you see the air gassing out of the secondary air holes? . I'm new here I have some designs to share and some ideas I need help with also .I wil post soon. Thanks again for sharing. David nz
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Mon Mar 23, 2015 6:00 am
Answering your questions, I only have air control for primary air. In this stove I did not make controls for secondary or tertiary air. In my other stoves I do not use the controls for secondary air. If I need to control secondary or tertiary air, I will just improvise a plug. To get a good secondary burn on all the stoves that I built, I just reduce as much as possible the primary air and close the flue dumper 50% to 70%. In this stove, of course I get good secondary burns, I tried to make a video of it, but the glare is too intense for the camera and this secondary burn is not clear. I did not try to close the secondary air, but I tried to close the primary air and there was secondary burn.
keepittoasty
Posts : 113 Join date : 2014-11-13
Subject: Re: Making progress on my new stove Mon Mar 23, 2015 6:04 pm
That is a good video Sir. Those Temps are outstanding. How did you choose the 8cm gap above the riser?
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Tue Mar 24, 2015 2:50 pm
In my stoves, all areas are related one with the other, some empirically I base on rules of thumb, others direct relations between parts. For example, The air dispensers have an exit area for the air, a little bit smaller than the area of air entrance. That is why I say, "I use square tube area dimensions y mm x z mm and I have t holes, w mm each", t x w is slightly smaller than y x z. If I have a round riser tube 5.5 inches, 132 mm internal diameter, total area is 13685 mm2. Now, what is the minimum gap I need between the top of the riser tube and the heat dispenser to allow free circulation of gases? This calculation will be made by the internal area (13685 mm2) of the riser tube divided by the perimeter (415 mm) of the riser tube. The result is 33 mm. I need a gap of 33 mm, but, if I what to be sure, I will add 20% more tolerance, that is about 40 mm. Now, because I am lazy and I had already the heat dispenser 1.03 m long, I decided not to cut 40 mm just to fit my calculations. Also, if the top plate of the heat dispenser is further away from the riser tube, it will heat less and will last longer...
keepittoasty
Posts : 113 Join date : 2014-11-13
Subject: Re: Making progress on my new stove Wed Mar 25, 2015 12:01 pm
thank you for explaining. Would there be any negative effect, that you could see, to having a much larger gap above the riser? say 60 cm?
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Wed Mar 25, 2015 2:02 pm
Not a negative effect for the materials, that is for sure. I am not a physicist or a thermodynamics engineer but I will try to explain based on my empirical experience. For sure there are benefits and disadvantages to approach or take further away materials from the fire. What I think is that you need to have a relation between stove walls size and fire size. If the stove is too big and the fire too small, the temperature of the walls is smaller when compared to the same size fire inside a smaller stove. But in the first case (big stove, small fire) chimney temperature will be smaller because gases had more time to expand and loose more heat. In my latest stove, the hottest place of the heat exchanger is just above the riser tube, not at the top plate. People also report that sometimes the top plate of the heat exchanger gets red hot on their stoves when this plate is too close to the riser tube (according to their dimensions). If I have used a 12 inch tube for heat exchanger instead of a 10 inch, probably I could have extracted more heat from the stove because I would give more time for gases to expand and chimney would be cooler. You see, there is a compromise between factors.
And no, I would not advise you to have a gap of 60 cm above the riser tube in a rocket stove heater. It would be a waste of material and temperature in the upper part of the heat exchanger would be too low and you would loose some practical aspects of that part of the stove like cooking food.
gadily Moderator
Posts : 1477 Join date : 2013-12-08
Subject: Re: Making progress on my new stove Thu Mar 26, 2015 6:30 am
thanks for info cao's ive never come across info to that extent so is worth a learn of it and also how different each build is per there usages
keepittoasty
Posts : 113 Join date : 2014-11-13
Subject: Re: Making progress on my new stove Thu Mar 26, 2015 6:57 am
Yes, thank you, that was really helpful. Ive read it multiple times. I'm glad that you are sharing so much of this knowlege! Thinking about heat output and sizing a stove prperly for its intended use really is a balance of proportions. I was wondering what you thought would happen if all your proportions and ratios stayed the same, could the exhaust exit tube coming from the heat exchanger be lower? What if the heat exchanger went all the way to the floor and the flu exit came out at floor level. Or maybe even sub floor level. What are your thoughts on this scenario as far as any performance changes you might expect.
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Making progress on my new stove Thu Mar 26, 2015 2:37 pm
You can see my videos on the reverse rocket stove and the "Wood stove idea / prototype" video. The flue exit was below the combustion chamber and the combustion would hardly work. Also Kevin Bacon (the Omega Stove), T2H and Jeff Crutchfield made experiments with flue level below the combustion chamber and got the same results as I did. It is true that many people place the flue exit at the same level of the combustion chamber and the stove works ok, but it is harder to light. Also, theoretically, the lower the flue exit is in relation to the combustion chamber, more heat you can extract from the stove, but there is a limit. Also, having the flue a little bit higher than the combustion chamber will avoid smoke to exit the combustion chamber into the living room when I open the stove to load it. Up until a certain point, you can compensate the disadvantages of having a higher flue exit by making a higher riser tube and a higher heat exchanger. It is all a question of proportions...
The factors "easy to light the stove", smoke exit when you open the door and compromise with heat extraction are the main factors that determined the location of the flue exit in my current stove.